The oil and gas industry uses metal products in virtually every aspect of business operations, including exploration, production, refining and pipeline transportation.
For example, a refinery is an industrial process plant where crude oil is processed and refined into more useful products, such as petroleum naphtha, gasoline and diesel fuel, base stock for asphalt, heating oil, kerosene and liquified petroleum gas. Oil refineries are large, sprawling complexes with extensive piping running throughout carrying streams of fluids between large chemical processing units.
The basic function of a refinery is to refine base stocks into finished products. This requires a separating process whereby crude oil is separated by fractional distillation (heating base stock in a fractionating tower). The fractions at the top of the tower have lower boiling points than fractions at the bottom. For example, the boiling point for gas is 20 degrees, gasoline is 150 degrees, kerosene is 200 degrees, diesel oil is 300 degrees, fuel oil is 370 degrees and “heavy ends” is 400 degrees or higher. The separated molecules are then moved to specialized processing units pipe and converted into finished products. The central mode of product transportation for all of this work is pipe.
Oil and gas refineries are typically a low margin, high capital investment business. As such, they must run continuously and efficiently to produce a net profit that justifies the investment.
It is therefore a significant problem for any refinery to not be running for a period of time. It is desirable to minimize any “down time” for part replacement and repairs. Since piping is the primary mode of product transport, an improvement in the lifespan of piping presents a substantial savings in cost, and increase in profitability, to the industry.
An increase in the lifespan of piping also lessens risk associated with product leakage. Product leakage can result in fire and fume injuries, as well as environment damage. The lifespan of piping is a paramount issue in the oil and gas industry.
Hardfacing is a process by which a harder material can be applied to a base substrate metal, typically by welding. Hardfacing can be used to improve the wear resistance of metal parts, since the harder material protects the surface of the metal parts to which it has been applied. New metal parts can be protected by hardfacing, and, similarly, worn metal parts can be restored using this process. The use of hardfacing could assist in the piping lifespan issues described above.
Wear resistance is an issue that has received attention within the oil and gas industry since it significantly affects costs in the aforementioned four major business operations.
Some research has led to inventions which are the subject of patents. For example, U.S. Pat. No. 3,936,295 to Cromwell et al. discloses the coating of surface properties of bearings and rotors through a plasma-spraying process that includes nickel-aluminium, nickel-molybdenum, tungsten carbide and an intermetallic alloy.
In the present invention, new metallurgical properties are applied to metal. An aspect of these new properties is the production of a hard-clad matrix that is substantially harder than unaffected parent material, and which is wear resistant, repairable, casing friendly, smooth, non-magnetic and cost efficient.
These and other objects and advantages of the present invention will be apparent from the following detailed description of the invention and the preferred embodiments thereof.